package cn.muqingfeng.util;

import java.util.Random;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import cn.muqingfeng.bbs.R;

public class Code {
	private static final char[] CHARS = { '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'j', 'k', 'l', 'm', 'n', 'p', 'q',
			'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U',
			'V', 'W', 'X', 'Y', 'Z' };

	private static Code bmpCode;
	private Context mContext;

	private Code(Context context) {
		super();
		mContext = context;
		Resources resources = mContext.getResources();
		width = resources.getDimensionPixelSize(R.dimen.code_width);
		height = resources.getDimensionPixelSize(R.dimen.code_height);
		font_size = resources.getDimensionPixelSize(R.dimen.code_size);
	}

	public synchronized static Code getInstance(Context context) {
		if (bmpCode == null) {
			bmpCode = new Code(context);
		}
		return bmpCode;
	}

	private static final int DEFAULT_CODE_LENGTH = 4;
	private static final int DEFAULT_LINE_NUMBER = 2;

	private final int width;
	private final int height;
	private final int font_size;
	// number of chars, lines; font size
	private int codeLength = DEFAULT_CODE_LENGTH, line_number = DEFAULT_LINE_NUMBER;

	// variables
	private String code;
	private Random random = new Random();

	// 验证码图片
	public Bitmap createBitmap() {
		Bitmap bp = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
		Canvas c = new Canvas(bp);

		code = createCode();
		c.drawColor(Color.WHITE);
		Paint paint = new Paint();
		paint.setTextSize(font_size);
		Rect rect = new Rect();
		paint.getTextBounds("ZZZZ", 0, 3, rect);
		int paddingTop = height * 3 / 4;
		int paddingLeft = (width - rect.width()) / 2 - 15;
		for (int i = 0; i < code.length(); i++) {
			randomTextStyle(paint);
			c.drawText(code.charAt(i) + "", paddingLeft, paddingTop, paint);
			paddingLeft += rect.width() / 4 + 5;
		}

		for (int i = 0; i < line_number; i++) {
			drawLine(c, paint);
		}

		c.save(Canvas.ALL_SAVE_FLAG);// 保存
		c.restore();//
		return bp;
	}

	public String getCode() {
		return code;
	}

	// 验证码
	private String createCode() {
		StringBuilder buffer = new StringBuilder();
		for (int i = 0; i < codeLength; i++) {
			buffer.append(CHARS[random.nextInt(CHARS.length)]);
		}
		return buffer.toString();
	}

	private void drawLine(Canvas canvas, Paint paint) {
		int color = randomColor();
		int startX = random.nextInt(width);
		int startY = random.nextInt(height);
		int stopX = random.nextInt(width);
		int stopY = random.nextInt(height);
		paint.setStrokeWidth(1);
		paint.setColor(color);
		canvas.drawLine(startX, startY, stopX, stopY, paint);
	}

	private int randomColor() {
		return randomColor(1);
	}

	private int randomColor(int rate) {
		int red = random.nextInt(256) / rate;
		int green = random.nextInt(256) / rate;
		int blue = random.nextInt(256) / rate;
		return Color.rgb(red, green, blue);
	}

	private void randomTextStyle(Paint paint) {
		int color = randomColor();
		paint.setColor(color);
		paint.setFakeBoldText(random.nextBoolean()); // true为粗体，false为非粗体
		// float skewX = random.nextInt(11) / 10;
		// skewX = random.nextBoolean() ? skewX : -skewX;
		// paint.setTextSkewX(skewX); // float类型参数，负数表示右斜，整数左斜
		// paint.setUnderlineText(true); //true为下划线，false为非下划线
		// paint.setStrikeThruText(true); //true为删除线，false为非删除线
	}
}
